NJDEP Updates Vapor Intrusion Technical Guidance

Posted on April 30th, 2012

The New Jersey Department of Environmental Protection (NJDEP) has developed guidance for professionals to use when evaluating and investigating the potential for vapor intrusion. Vapor Intrusion is the migration of volatile chemicals from the
subsurface into overlying buildings and poses significant health risks to
occupants of the impacted buildings. This new guidance was developed in conjunction with a stakeholder group, consisting of industry representatives and environmental professionals. The first version of the guidance was released in 2005, and the updated Vapor Intrusion Technical Guidance is now available here.

The document is significantly altered from the previous 2005 version. The following are a few key differences:

  1. Suggested sample frequencies for vapor intrusion sampling
  2. Specific criteria for gasoline releases
  3. Specific limitations on using sub-slab sampling in buildings where a shallow water table exists
  4. Comprehensive information on mitigation strategies including design, mitigation and post-mitigation procedures and monitoring

In addition, the document no longer contains the vapor intrusion screening levels. LSRPs and other investigators are currently using
the 2005 screening levels. Those screening level tables are currently published on the NJDEP website. The NJDEP (not the stakeholder group) is reevaluating the current vapor intrusion screening levels and changes to the levels are expected. No specific timetable
has been provided for when the revised screening levels will be released or the format that the screening levels will be released in, it is possible that the screening levels will become remediation standards. 

Peter Sorge of JMS participated
in the stakeholder group that worked closely for over a year to revise the
initial guidance document. The stakeholders worked together to develop a
document that provides practical flexible guidance that is protective of human health and the environment. 

For additional information see the following link: 


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